Shortcuts to adiabaticity in Fermi gases

TL;DR

This paper demonstrates the use of shortcuts to adiabaticity (STA) to rapidly and efficiently control the dynamics of Fermi gases across different interaction regimes, including non-interacting, strongly coupled, and high-temperature states.

Contribution

It introduces and experimentally implements STA protocols for Fermi gases, achieving frictionless expansion and controlling viscous hydrodynamics in various regimes.

Findings

Friction-free superadiabatic expansion in the unitary regime.

Effective STA protocols in high-temperature viscous hydrodynamics.

No residual excitations in the final state after STA.

Abstract

Shortcuts to adiabaticity (STA) provide an alternative to adiabatic protocols to guide the dynamics of the system of interest without the requirement of slow driving. We report the controlled speedup via STA of the nonadiabatic dynamics of a Fermi gas, both in the non-interacting and strongly coupled, unitary regimes. Friction-free superadiabatic expansion strokes, with no residual excitations in the final state, are demonstrated in the unitary regime by engineering the modulation of the frequencies and aspect ratio of the harmonic trap. STA are also analyzed and implemented in the high-temperature regime, where the shear viscosity plays a pivotal role and the Fermi gas is described by viscous hydrodynamics.